Effects of TRH and PS-24 on colonic temperature and motor activity of rats: possible role of dopamine.
TRH and PS-24 (a TRH peptidase resistant analogue) induce different effects on body temperature and motor activity in rats kept at 4 degrees C. PS-24 induced hypothermia, but TRH did not. PS-24 induced hypermotility, while TRH induced slight hypomotility. The thermal effect of TRH in hypophysectomized rats was similar to its effect in control intact rats, but PS-24 induced marked hypothermia in hypophysectomized rats. While TRH partially blocked d-amphetamine-induced hypothermia, PS-24 induced marked hypothermia in hypophysectomized rats. While TRH partially blocked d-amphetamine-induced hypothermia were blocked in olfactory tubercle-lesioned rats. The data indicate that the thermal effects of PS-24 are mediated by the dopaminergic neurons in the nucleus accumbens and are reversible by pretreatment with haloperidol in hypophysectomized rats. In addition, no correlation between the effects of the treatments on thermoregulation and motor activity was found.
D000818:Animals; D001831:Body Temperature / Q000187:drug effects*; D003913:Dextroamphetamine / Q000494:pharmacology; D004298:Dopamine / Q000502:physiology*; D004357:Drug Synergism; D006220:Haloperidol / Q000494:pharmacology; D007016:Hypophysectomy; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D051381:Rats; D013973:Thyrotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology*
C031926:montirelin; D013973:Thyrotropin-Releasing Hormone; D006220:Haloperidol; D003913:Dextroamphetamine; D004298:Dopamine